Method for separating hydrocarbons and making mercaptans



Oct' 16, 1945 D. E. BADERTscHER rs1-AL.v 2,387,224

METHOD FOR SEPARATING HYDROCARBOS AND MAKING MERCAPTANS Filed Feb. 6, 1943 2 Sheets-Sheet 1 ger Oct. 16, 1945. D. EQBADERTSCHER :f1-Al.` 2,387,224

METHOD FOR SEPARATING HYDROCARBONS AN) MAKING MERCAPTANS Filed Feb. 6, 1943 2 sheets-sheet 2 ATTO RN EY tures from about 32 F. to about 100 Patented Oct. 16, 1945 'NITED STATE s- PATENT oFFicE METHOD FOR SEPARATING HYDROCAR- i BONS AND MAKING MERCAPTANS Darwin E. Badertscher, Woodbury, N'. J., and Harry L. Coonradt, Camp Lee, Va., and Duncan J. Crowley, Penns Grove, N. J., assignors to Socony-Vacnum `il Company, Incorporated, a corporation of New York Application February 6, 1943, Serial No. 474,924

16 Claims.

- art that oleflns will react with B2S in the presence of various catalysts to form mercaptans.'

For example, it has been suggested that olens of at least eight .carbon atoms will react in the liquid phase in the presence of certain catalysts, at time intervals of from 6 to '72 hours, to form sulfur-containingv compounds including sulfldes and mercaptans. The present invention' distinguishes over the foregoingin that our catalytic treatment is carried out in the vapor phase with a very brief contact time which may vary from a fraction of a second to several minutes. It has also been Suggested (U. S. Patents 1,836,171 and 1,836,183) that olenswill react with H28 in the resence of certain catalysts, such as fullers earth, to form sulfur-containing compounds including mercaptans. Patent 1,836,171 has to do with the reaction of liquid olefins and Has in the presence of fullers earth at tempera- (0 C. to about 38 C.); and Patent 1,836,183 is directed to the reaction of olen vapors and HzS in the presence of fullers earth at atmospheric tem- More verted to their corresponding tertiary mercaptans when the hydrocarbon mixture in the vapor Y phase and in admixture with B2S is passed over a suitable catalyst with the temperature of the catalyst or reaction zone maintained within certain preferred limits, depending upon the nature of the catalyst, the pressure in the reaction zone,

etc.

Accordingly, the process of the present invention may be employed to treat a mixture of hydrocarbons for ultimate use in an. operation where the tertiary base olens, such as isobutylene and tertiary base amylenes, are harmful contaminants, and to eiect the removal of such contaminants, at the same time producing valuable organic chemicals from the' tertiary base olens removed. It has been shown, for example, that isobutylene inv a butene mixture retards the formation of olefin S02 polysulfone resins andthe process of the present invention may be used to provide a butene mixture devoid of isobutylene for use in such resinfying reaction.

` Tertiary bas'e olefins as defined herein are those olefins characterized by the presence of g5 the tertiary olefin linkage perature and higher temperatures. The present i invention distinguishes over the earlier patent- 1,836,171-in that' our catalytic treatment with fullers earth is carried out in the vapor phase and is extremely effective at temperatures in vexcess of the temperature range dened-therein.

And the present invention over Patent 1,836,183 in the discovery of a temperature range over which the vapor phase treatmencontemplated herein is operative.

Another fundamental distinction between pre viously proposed processes and the novel process of the present invention is predicated upon our discovery that the catalytic process contemplated herein is selective for the conversion of certain olens to their corresponding mercaptans. For example, the present invention is -based upon the discovery that the C- and C-5 y tertiary base oledns, isobutylene, trimethyl ethylene and unsymmetrical methyl ethyl ethylene (of which the latter two are tertiary base amylenes) contained in a mixture ofhydrocarbons are con- R.c=c/ Y. Y where R. is a low molecular weight alkyl group, `such as methyl. Typical members of this class. and preferred herein, are isobutylene` nic 2c=cna and trimethyl ethylene n (moho- --ont The present invention also provides a highly effective and economical method for obtaining the individual tertiary mercaptan from its corresponding tertiary base olen, i. e., tertiary butyl mercaptan from isobutylene, and tertiary amyl` mercaptan from trimethyl ethylene and unsymmetrical. methyl ethyl ethylene, respectively.

These tertiary mercaptans may be obtained as an incident to the separation of thev corresponding tertiary base oleiins from a hydrocarbon mixture as aforesaid, or they may be obtained by the vapor phase reaction of the pure tertiary base olefin with hydrogen sulde under similar Y' sulfonic acids, non-plastic clay-type catalysts typified by fullers earth, alumina-silica type synthetic catalysts and halogenated acids, such as trichloracetic, etc. For the purposes of the present invention, preference is given herein to non-plastic clay-type catalysts typified by i fullers earth; other catalysts are made the subject matter of companion applications. There is little, if any diminution in the effectiveness' able to dry the gases prior to contacting them with the catalyst. The drying of the gases prior to introduction into the reactor presents no difiiculties and is routine procedure to those familiar with the chemical and petroleum arts.

We have discovered that the reaction of hydrogen sulfide with a tertiary oase oleiin to form a tertiary mercaptan by the process contemplated herein is quite sensitive to temperature as a means for controlling the yield of mercaptan, and it is a further important object of this invention to provide a process of the class described wherein the temperature is controlled to aiord a maximum yield of the mercaptan.

Further details in a Preferred procedure forcarrying out the process contemplated by this invention may be obtained from thefollowing description taken with accompanying drawings, Iwhich are chosen for illustrative purposes only and in which: Figure 1 is a diagrammatic view illustrating one form of apparatus which may be employed in practicing the process of this invention: Figure 2 is a sectional elevation showing in enlarged detail a typical form of reactor which may beemployed inthe system shown in Figure Y 1; and Figure 3 is a graph with a curve showing the eiiect of temperature variations upon the yield of tertiary butyl mercaptan in the process contemplated therein.

In Figure 1, reference numeral ii indicates-a reactor which is. shown in Figure 2 as embodying a shell I2 which may -be of circular or other suitable cross-sectional shape, such shell being provided near its top with a partition plate I 3 having.

a plurality of openings I4, which'receive the upper ends of tubes I5 secured therein in any suitable manner, such as welding (not shown). The

lower ends oi' the tubes i5 are supported in openings I6 through a bottom partition plate il secured near the bottom of the shell i? in any suitable manner so as to form a chamber i3 in the shell between plates Il and I3. For the purpose of controlling the temperature within the tubes i 5, a suitable heat exchange medium is circulated through the chamber I8 from an inlet 20 to an outlet 2 l The top of the chamber or shell l2 is provided witha cover 22, which, with the top partition plate I 3, forms a chamber 23 in the top of the shell adapted to receive reaction vapors through -an inlet 2d, which vapors enter the various tubes from the chamber 23, as indicated by the arrows, The bottom of the shell `I 2 is provided with a bostomcover 25, through which the products of re-l action pass from the tubes I 5 into the product outlet 26. The bottoms of the various tubes I5 are provided with a suitable mesh material to support l assassins beneath'tneboaom plate n'by similarly per iorated plate Il'.

As aforesaid, the reaction contemplated herein is quite sensitive to temperature control: and although the length and'size of the reaction tubes I5 and the relation between the total volume of the chamber I 8 and the volume within such chamber which is occupied 'by the reaction tubes may be varied over relatively wide limits, it is to be understood that the relationship between these various factorathe temperature of the heat exchange medium, and the rate at which heat exchange medium is circulated through the charn- .bei-I8 should be so adjusted as to maintain the temperature in the reaction zones of the various catalyst tubes I5 within the range for most eiiicient operation, as will be hereinafter discussed.

Referring back to Figure l: reference numeral 30 indicates a conduit adapted to carry hydrocar- 'bons through a meter M into the reactor inlet 4 conduit 24.- This conduit is shown as passing through a pre-heater or vaporizer 32 through which a hot heat` exchange medium is circulated by means oi connections 33 and s3. Hydrogen sulde is introduced into the system through the valved connection 35 and a meter M', such hydrogen suliide being optionally introduced into the inlet 24 on either side oi the vaporizer 32 by means of valved connection 3B or iid.

With regard to the vaporizer or pre-heater 32, it is to be understood that other suitable means may be provided 'for insuring that the reactants are in the vapor phase when they pass into the catalyst tubes in the reactor. For example, it may -be found, particularlyafter the reaction has been started, that there is sumcient heat in the reactor itself to edect this vapor-ization, or heater coils may be provided in the chamber 2t, as will readily'appear to those skilled in the art.

Suitable means for controlling th temperature ci the heat exchange medium entering the reactor through' inlet 2li are indicated by reference numeral 40. The temperature-control means do may be any suitable heat exchange device and can be either manually or automatically operated in any manner well known to those skilled in the art. Also, if desired, the heat exchange medium may be recirculated from the outlet 2i through the temperature control do to the inlet 2t as will be obvious to those skilled'in the art. Any suitable heat exchange medium, such as water, may be employed to control the temperature in the chamber it of reactor I I. v

Reference numeral 5I indicates a cooler or condenser through which the product-outlet conduit 2S passes into conduit section 2t', which opens 65. can then be Withdrawn together with the polychamber 2l through a valved liquid-outlet conmerization products of reaction from the seaied nectlon 45, or such temperature in the cooler si may be controlled so that only the high boiling products are condensed, substantially all of the mercaptan, together with the hydrogen suliide and hydrocarbon gases, being conducted in such case from the sealed chamber 2l through a va.

por-outlet conduit 41 to the bottom of a scrubbing tower 48.

The top ci' the scrubbing tower 48 is provided with a gas vent 50 and an inlet conduit 5l for a scrubbing solution, such as aqueous caustic soda. The bottom of the scrubber 48 has an outlet 52 which connects with the bottom of a still or stripper 5B. Outlet connection 52 is equipped with a drainage valve 53. The still or stripper 54 is shown as being equipped with a high-pressure.l steam coil or other suitable source of heat 55 and has an outlet 56 which connects through a condenser 51 with a separator 58. The separator 5B is provided with a valved mercaptan outlet 59, a gauge glass 13 to facilitate removal of the mercaptan, and a valved water outlet BIB. The water outlet 60 connects through a valve Bi with a water return pipe B2, which in turn is shown Vas connecting with the causticreservoir 6l. The still 5d is shown as being equipped with a caustic outlet conduit 6d which includes a liquid caustic well 6c', the purpose ofvwhich is to prevent mercaptan vapor from leaving still 54 by the conduit Sd. Caustic passes through conduit 5d to a caustic cooler 65 and exits therefrom through outlet 6B to the caustic reservoir BA1. The caustic reservoir is tted with a drainage means G6. The caustic reservoir is alsofequipped with a conduit 69 which connects with the intake side of a pump 53. The discharge side of pump SSis shown tan, high boiling materials, traces of unreacted- HzS and traces or unreacted isobutylene. Similarly, when thahydrocarbon used is a tertiary base amylene, tertiary amyl mercaptan isiormed and the eiliuent gases will contain unreacted H25; unreacted tertiary base amylene and polymers of 'said amylene in addition t0 this mercaptan.

When the hydrocarbon used is a .hydrocarbon mixture containing a tertiary base olen (or tertiary base olens), such as, for example, isobutylene, secondary oleins, normal olens, and saturated hydrocarbons, only the tertiary base olefin (or tertiary base oleiins) is converted to as connecting withinlet conduit 5l .of scrubber d8. Means indicated at 'lll are provided foradding fresh caustic when desired; and means indicated at 'H are provided for adding fresh water to the system. A water drain isshown at l2, and

the last-described connections are shown as being provided with suitable valves for 'controlling the addition or discharge of the various media.

In practicing the process contemplated with an apparatus of the type shown .in Fig'- ures l and 2, the tertiary base oleln, yeither alone or in admixture with other hydrocarbons, and the hydrogen sulfide are metered into the system through meters M and M'. 'Ihe proportions of these two reactants may be varied over relative.

ly wide limits, but for optimum results it is prefferred that these proportions be such that the hydrogen sulfide be slightly in excess o f the molar equivalent required to react with the tertiary base olen present.

The admixture of hydrocarbon and B2S is introduced into the reactor il in the vapor phase, as by passing the hydrocarbon through the va l porizer 32 prior to admixture with Has.V Upon herein entering the reactor i l, the hydrocarbon HzS vapor mixture passes through the catalyst tubes IE where it contacts the'catalyst for a short period vof time. It is a feature of the process contemplated herein that the period of catalyst contact is very short. With a catalyst of the type described hereinabove, contactV times of from about a fraction of a second to about several minutes serve the purposes of this invention, but in general, 'a contact time of a fewv seconds is preferred. The *temperature of the heattransfer.

medium in chamber I8 is controlled by the temperature control di! so that the temperature of vthe catalyst zone within the tubes i5 is maintained within the range that will give the desired 'conversion As aforesaid, the process contemplated hereinlisquite sensitive to temperature.

We have found, for example, thatthe process is operative between the limits of 55 C. and about 200 C., but for optimumconver'sion a more closely denedrange of temperature is necessary. This will be discussed in further detail hereinafter.

When in contact with the catalyst in the catathe corresponding mercaptan. Other vhydfrocarmay be maintained such that only the high boiling products are condensed, in which case, the

condensate hows into the `sealed chamber V2'! and from which it can then be withdrawn through the outlet connection c5. The unreacted hydrocarbons, unreacted Has and the tertiary mercap-4 tan, such as tertiary butyl mercaptan, are not condensed when such a temperature is maintained in the condenser di, and flow through the vapor-outlet conduit al to the bottom of the scrubbing tower rid. If desired, the temperature of the condenser di may be adjusted so that the greater portion of the tertiary butyl mercaptan is condensed along with the high boiling matesrials. This condensate withdrawn through connection d5 may then be distilled in a suitable distillation tower (not shown) to separate the ter'- tiary mercaptan from thev polymerization products. Y `The uncondensed portion of the reaction mixture rises in the scrubber @d and contacts a downstream of scrubbing solution, such as aqueous caustic soda whereupon tertiary mercaptan (butyl or amyl, or both, depending on the tertiary base olefin or oleflns in the charge). and hydrogen sulide are converted respectively tothe Vcorre- Y t2 to the still iid. High-pressure steam or other heating medium passes throughv th'e coil 55 in the still 5d, thereby heating the caustic solution to an elevated temperature. `0n heating thef caustic solution, the alkali mercaptide is coni lyst urbes BB under the conditions described here-v 'I5 vetted to the corresponding tertiary butyl or'terv tiary amyl mercaptan which. along with some water, distills from the solution. 'I'he tertiary mercaptan-water vapors rise to the outlet line I, flow therethrough to the condenser 5l where' they are'condensed and from which th'e condensate ows to the separator 5l. 'I'he condensate separates herein (58) into an upper layer of mer- The mercapled-by plotting the yield obtained in each prep- It -will be apparent from the foregoing-that when the original hydrocarbon mixture contains a mixture of the preferred tertiary base oleflns,

isobutylene and trlmethyl ethylene, for example,

the mercaptan layer withdrawn through the' valved outlet 59 will be afmixture of tertiary butyl and tertiary amyl' mercaptans. These mercaptans can then be separated from each other by suitable separation means, such as by distillation (means not shown) The lower water layer'is allowed todrain from the'bottom of the separator 58, through the water outlet 6l.' It is recombined, inpassing through th'e valve 6i and the water-return pipe l2. with the caustic solution which hasV been discharged from the still 54. This caustic solution has passed through conduit M, well 64', th'e cooler 6B, conduit 68, to caustic reservoir 61.

This cold caustic solution, which contains some alkali sulfide, combined with water from the separator 58 is pumped by means of the pump 63 to the caustic scrubber It through the inlet conduit 5|. If, however, said caustic'solution from the still 54 tends Y to accumulate an appreciable amount of alkali sulfide, it can be removed from the system by means of the drain, and can be replaced with a desired amount of fresh caustic through the means lo. This is necessary when an appreciable amount of unreacted HaS is present in the eiiluent gases from the reactor -ll and v which reacts with caustic soda in the scrubber IB to form alkali sulfide. If it isnecessary to introduce additional water into the system to add to the caustic solution cooled in, the cooler 65, fresh water means1I.

The selective action of H28 upon tertiary base oleiins, such as isobutylene and isoamylenes, is

influenced by a number of factors such as tem-. perature. pressure, contact time and rate of now of reactants, proportions of reactants, etc. As

can be introduced through the kis fromfabout 7 to about 200 100 grams of fullers earth wasI ume and height in the column were 200 cc. and

and hydrogen sulfide under the following conditions which are similar to th'ose described hereinabove. It will be clear, then, that the curve was prepared-following several preparations of tertiary butyl mercaptan from isobutylene and hyydrogensulflde under the following conditions .wherein only the reaction temperature was vararation against the reaction temperature used therein and connecting th'e points thus plotted.. A. reaction chamber containing a single catalyst hours to about 61/2 hours with contact times from about 3 minutes to about 4 minutes, which was inuenced by temperature, catalyst volume, etc. Each yield of tertiary butyl mercaptan was based upon that fraction of reaction product boiling from 63 C. to 66 lC. at atmospheric pressure.

The curve clearly shows that the process contemplated herein with fullers earth as the catalyst is operative over the temperature range of 55 C. to about 125 C. and the slope of the curve from about C. t0 about 125 C; indicates that the process contemplated herein isoperative to about temperatures of the order of 260 C. Thus, it appears 'that the operative temperature range C. A quantity of used; and the vol- 52.5 cms., respectively, It is seen that at about 55 C. a. yield 'of about 5% is obtained. The yield increases with increase of temperature untilthe maximum yield-about %`-is obtained .in the neighborhood of 80 C. Thereafter, further in'- crease of temperature makes for smaller yields until at about C., the'yield is only about 55%, and at about C. the slope of the curve indicates that the yield is only about 35%.' For practical purposes where yields of 60% and greaterare desired, the curve indicates that temperatures we have previously indicated, temperature is the most-'important and most critical of these in-` fluencing factors. The reaction ofthe tertiary .baseoletlm such as isobutylene or isoamylenes,

andhydrogen sulfide whereby the corresponding tertiary mercaptan is formed is slightly exother-` mic. Therefore, invorder' that the temperature of the reaction mixture be controlled within the desired limits, the heat of reaction should be uni-` formly and readly withdrawn from the reaction' zone. This may be accomplished by a proper control of the temperature and rate of flowof the heat transfer medium in theV reactor. 'I'he sensitivity of this reaction to temperature in the' presence of fullers earth is .illustrated by the curveinFlgure3.

Referring now to Figure 3, thecurve is a tem- '10 perature-yield curve with temperature plotted alongthe abscissa and yield of tertiary butyl v"nercaptanplotted along the ordinate. Each point on the curve represents a single preparation of tertiary butyl mercaptan from isobutylene within the range of about 65 C. to about 110 C.

may be used. Similarly, the curve indicates that temperatures within the range of about '10fI C. to about 90 C. may be used to obtain yields of 75% and greater. 'Ihe curve also indicates that the temperature range-0 C. to about 38 C.-proposed in the aforesaid Patent 1,836,183, is inoperative for the process contemplated herein.

While the curve was obtained with the operating conditions described above, it will be understood that the slope and breadth of this curve may 'change with changes in one or more operating conditions. For example, various proportions of reactants may be used instead of three liters of each gas, hydrogen sulfide and isobutylene. In

' general, however, it appears that the-curve substantially represents the catalytic action of fullers earth in the conversion of the C--i and M tertiary base olens to their corresponding tertiary mercaptans.

It is one feature of this invention that high pressures are not required. On the contrary, atmospheric or, at most, pressures only slightly greater than atmospheric are used. In order that the reaction be carried out in the 'vapor phase, it is necessaryv that the pressure be less than that pressure at which liquefaction of the hydrocarbon would occur at the operating. temperature. It-

will readily be seenfthat the use of pressures from about atmospheric to about 4 atmospheres are not such as to require the use of expensive high pres- 4 mercaptan.

sure reaction chambers. This. loi? course, is a decided economic advantage.

As aforesaid, the proportions of reactants for our process obviously can be varied considerably. Theoretically, the optimum molar ratio of tertiary base olen to hydrogen sulde wouldf b e 1:1. In some cases, however, maximum yields are obtained when a slight excess of HzS is used.

Tertiary base oleiins are notorious for their tendencyv to polymerize and this polymerization reaction tends to compete with the addition reaction with the resultant formation ci high boiling polytertiary basejolefins. An excess of Hrs, therefore, v

will increase the yield of mercaptan by aiording greater opportunity for the tertiary base olefin- HzS reaction. The factor of the molar ratio of the reactants naturally will be regulated by. the economics of the particular case at hand, that is, by the relative costs of hydrocarbon and ms, and of their handling and recovery.

From the foregoing description and examples, it will be seen that the process contemplated herein provides a convenient means -for separating tertiary base olens from a mixture of hydrocarbons which are to be used in subsequent procedures where the tertiary base olefin would be an undesirable contaminant. It also provides an economical process for the synthesis of tertiary mercaptans, such as tertiary butyl mercaptan and tertiary amyl mercaptan from either a hydrocarbon mixture containing the corresponding tertiary base olen vor the corresponding tertiary base olen in the pure form. Ii the hydrocarbon reactant contains several tertiary base olens, the mercaptan product will be a mixture of the corresponding tertiary mercaptans which can be separated into its various components by fractionation.

It is to be understood that this invention is not to be limited to the foregoing typical illustrative examples of the same, but is to beconstrued broadly as dened .by the language of the appended claims.

This application is a continuation-impart of our copending application Serial No. 461,116, led October 7, 1942.

We claim: I

1. The method of making a-tertiary mercaptan from a monomeric tertiary base olefin con- 5 taining from four to iive carbon atoms which comprises, passing said tertiary base olen in the vapor phase with hydrogen sulde through a reaction zone containing a non-plastic clay-type catalyst, regulating the ow of said reactants' through said reaction zone to provide therein ,a contact time from a fraction of a second to several minutesand maintaining the temperature of said reactants therein between about C. andabout 125 C., whereby said tertiary base olefln is converted to the corresponding tertiary .v 2. The method ci making a tertiary mercaptan from a monomeric tertiary base oleiin containing from four to ve carbonatoms which comprises, passing said tertiary base olen in the vapor phase with hydrogen suliide through a reaction zone containing iullers earth, regulating the flow of said reactants through said reaction zone to provide therein a contact time from a fraction of a second to several minutes and maintaining the temperature of said reactants therein between about 55. C. and about`l25 C., whereby said tertiary base olen is converted to the corresponding tertiary mercaptan.-

3. The method of making a tertiary mercaptan from a monomeric tertiary base olen contaming iromiour to kfive carbon atoms which comprises, passing said tertiary base olen in .the vapor phase with hydrogen sulde through a reaction zonecontaining fullers earth, regulating the ow of said reactants through said reaction zone to provide therein a contact time iromol fraction of a second to several minutes and maintaining the temperature of said reactants therein between about C. and about V95 C., whereby said tertiary base olen is converted to the corresponding tertiary mercaptan.

4. The method of making a tertiary mercaptan from a monomeric tertiary base olei'ln containing from four to ve carbon atoms which comaction zone to provide therein a contactitime from a fraction of a second to several minutes, maintaining therein a pressure from about atmosphericto about four atmospheres and maintaining the temperature of said reactants therein between about 55 C. and about 125 C., whereby said tertiary base olefin is converted to the corresponding tertiary mercaptan.

5. The method of making a tertiary mercaptan from a monomeric `tertiary base olefin containing from four to five carbon atoms which comprises,l passing said tertiary base olefin in the vapor phase with a slight excess of hydrogen sulfide through .a reaction zone containing iu'llers earth, regulating the iiow of said reactants through said reaction zone to provide therein a contact time from a fraction of a second tovsev- `eral minutes and maintaining the temperature of said reactants therein between about 55 C. and about 125 C., whereby saidtertiary base olefin is converted to the corresponding tertiary mercaptan.

'6. The method of making tertiary butyl mercaptan from isobutylene which comprises,' passing isobutylene in the vapor phase with hydrogen sulfide through a reaction zone containing fullers earth, regulating Y the `ow of said reactants through said reaction zone to provide therein a contact time from a fraction of a second to several minutes and maintaining the temperature of said reactants therein between about 65 C. and and about 95 C., whereby isobutylene is converted to tertiary butyl mercaptan.

'7. The method of making tertiary amyl mercaptan from trimethyl ethylene which comprises, passing trimetliyl` ethylene in the lvapor phase with hydrogen suliide through a reaction zone containing fuller's earth, regulating the flow oi said reactants through said reaction zone to provide therein a contacttime from a fraction of a second to several minutes and maintaining the temperature of said reactants therein between about 65 C. and about 95 C., whereby trimethyl ethylene is converted to tertiary amyl mercaptan.

8. The method of making tertiary amyl mercaptan from unsymmetrical methyl ethyl ethylene which comprises, passing k unsymmetrical -methyl ethyl ethylene in the vapor phase with hydrogen sulde through a reaction zone containing fullers earth, regulating the iiow of said reactants through said reaction zone to provide V metrical methyl ethyl ethylene is converted tertiary amyi mercaptan.

'9. The method of selectively separating a monomeric tertiary base olen containing from four to iive carbon atoms from` ahydrocarbon` mixture containing said tertiary base olen, a

normal olen, a secondary oleiln-an'd a saturated.

hydrocarbon, which comprises: admixing said hydrocarbon mixture with-hydrogen sulde:

passingl the reaction mixture thus formed in the vapor phase through a reaction zone containing a non-plastic clay-type catalyst, regulating the -ilow of said reaction mixture through said reaction zone to provide a very brief contact time therein and maintaining the temperature of said v reaction mixture. therein between about 55 C.

and about 125 C., whereby said tertiary base oleiln is converted to the correspondingtertiary mercaptan; and separating said mercaptan fromy the reaction product so obtained.

10. The method o! selectively.. separating a monomeric tertiary base oleiln containing from a verl brie! contact-.torrie,thereinr and maintain? ing the temprature of 'said reaction therein between about 55 C. and about A125"^C.. whereby said tertiary base olefin is convertedto the correspondingtertiary mercaptan; and separating said mercaptan from the reaction product so obtained.l

13. The method of selectively separating monomerio' tertiary base oleiins containing from four to ve carbon atoms troma hydrocarbon mixture containing said tertiary base olens, a normal olefin, a secondary oleiln and a saturated hydrocarbon, which comprises: admixing said hydrocarbon mixture with hydrogen sulnde: passing the reaction'mixture thusi'ormed in the vapor phase through a reaction zone containing fullera earth, regulating the ilow'of said reaction' mixture through said reaction zone to provide a very four to-nve carbon atoms from a hydrocarbon mixture containing said tertiary base, olefin, a normal olenn, a secondary olenn and a saturatedhydrocarbon. which comprises: admixing said hydrocarbon mixture with hydrogen sulfide; passing the reaction mixture thus formed in the vapor phase through a reaction zone containing 'fullers earth, regulating the ilow of said reaction mixture through said reaction zone to provide a very brief' contact time therein and maintaining the temperature oi' said reaction mixture therein between about 55 C. and about 125 C., whereby said tertiary base oleilnis converted to the cor- [responding tertiary mercaptan; and separating,-

said mercaptan from the reaction product so obtained.

` 11."I 'he method o tvselectively separating a monomeric tertiary base oleiin containing from four to tive carbon atoms from a hydrocarbon mixture'containing said tertiary base o1en, ,a

normal oleiln, a secondary oleilnand a saturated h'y'irocai'bon,`v whichcomprises: admixlng said hydrocarbon mixture with hydrogen sulfide; passing the reaction mixture thus formed in the vapor phase through a reaction zone containing !uller's earth. regulating the iiow of said reaction mixture through said reaction zone to pro- .vide .a very brief contact time therein and maintaining the temperature of said reaction mixture therein between about 65 C. and about 95 C.,

whereby said tertiary base olenn is ,converted to the corresponding tertiary mercaptan; land separating said mercaptan from the reaction product so obtained. i f y A.

12. The method of selectively separating va.

" `monomeric tertiary base olefin containing from four to nve carbon atoms from a hydrocarbon mixture containing said tertiary base olen, .'a normal olefin, a secondary olenn and a saturated hydrocarbon, which comprises: admixing said hydrocarbon mixture with a slight excess, based on tertiary base olein, oihydrogen sulnde; passing the reaction mixture thus; formed in the vapor phase through a reaction zone containingA iullers earth, regulating the Vqow'of said reaction Y vapor with hydrogen sulnde in the presence oi' mixture lthrough said reaction zone to provide fullers earth, the improvement which comprises: regulating the now of said olefin' vapor and hydrogen sulde with respect to said fuller's earth to provide a contact time therein from a fraction vof a second to several minutes and maintaining a reaction temperature therein between about 65 C. and about 95 C.

15. In a method for making a' tertiary mercaptanby passing a vapor phase mixture con'- taining a monomeric tertiary base olefin and hydrogen sulfide through a reaction zone containing fulie'r's earth, the improvement' which comprises: regulating the ow of said vapor phase mixture through said `reaction zone to provide therein a contact time from a fraction o! a lsecond to several minutesan'd maintaining the temperature of said vapor phase mixture v therein between about 65 C. and about 95 C.

16. 'Ihe methode! selectively separating a monomeric tertiary base oleiln containing from 4 four to nve carbon atoms from a hydrocarbon mixture containing said tertiary' base olen and 4. at least one hydrocarbon other' than a tertiary base oleiin, which comprises: admixing said hydrocarbon mixture with drogen 'sulncie:l

the reaction mixture thus formed in the vapor A phase through a reaction zone containing a non'- plastic clay-type catalyst; regulating the ilow of said reaction mixture through said reaction-zone i to provide a very brief contact time therein and '60 maintaining the temperature ofsaid reaction mixture therein between about 55 C.V'and about 125 C. whereby said tertiary base ole'lin isconverted to the corresponding tertiary mei-captan; and separating said mercaptan from the reaction product so'obtained.

' DARWIN' HARRY L. C'OI)NRADT.l DUNCAN .1.*C1t0WlillY2` 

